Beispiel #1
0
 public void write(File out, boolean allowOverwrite) throws IOException {
   final ImageInfo imi =
       new ImageInfo(
           pixelWidth,
           pixelHeight,
           8,
           (4 == bytesPerPixel) ? true : false); // 8 bits per channel, no alpha
   // open image for writing to a output stream
   final OutputStream outs =
       new BufferedOutputStream(IOUtil.getFileOutputStream(out, allowOverwrite));
   try {
     final PngWriter png = new PngWriter(outs, imi);
     // add some optional metadata (chunks)
     png.getMetadata().setDpi(dpi[0], dpi[1]);
     png.getMetadata().setTimeNow(0); // 0 seconds fron now = now
     png.getMetadata().setText(PngChunkTextVar.KEY_Title, "JogAmp PNGImage");
     // png.getMetadata().setText("my key", "my text");
     final boolean hasAlpha = 4 == bytesPerPixel;
     final ImageLine l1 = new ImageLine(imi);
     if (isGLOriented) {
       // start at last pixel at end-of-buffer, reverse read (OpenGL bottom-left -> PNG top-left
       // origin)
       int dataOff =
           (pixelWidth * bytesPerPixel * (pixelHeight - 1))
               + // full lines - 1 line
               ((pixelWidth - 1) * bytesPerPixel); // one line - 1 pixel
       for (int row = 0; row < pixelHeight; row++) {
         int lineOff =
             (pixelWidth - 1)
                 * bytesPerPixel; // start w/ last pixel in line, reverse store (OpenGL bottom-left
                                  // -> PNG top-left origin)
         if (1 == bytesPerPixel) {
           for (int j = pixelWidth - 1; j >= 0; j--) {
             l1.scanline[lineOff--] = data.get(dataOff--); // // Luminance, 1 bytesPerPixel
           }
         } else {
           for (int j = pixelWidth - 1; j >= 0; j--) {
             dataOff = setPixelRGBA8(l1, lineOff, data, dataOff, hasAlpha);
             lineOff -= bytesPerPixel;
           }
         }
         png.writeRow(l1, row);
       }
     } else {
       int dataOff =
           0; // start at first pixel at start-of-buffer, normal read (same origin: top-left)
       for (int row = 0; row < pixelHeight; row++) {
         int lineOff = 0; // start w/ first pixel in line, normal store (same origin: top-left)
         if (1 == bytesPerPixel) {
           for (int j = pixelWidth - 1; j >= 0; j--) {
             l1.scanline[lineOff++] = data.get(dataOff++); // // Luminance, 1 bytesPerPixel
           }
         } else {
           for (int j = pixelWidth - 1; j >= 0; j--) {
             dataOff = setPixelRGBA8(l1, lineOff, data, dataOff, hasAlpha);
             lineOff += bytesPerPixel;
           }
         }
         png.writeRow(l1, row);
       }
     }
     png.end();
   } finally {
     IOUtil.close(outs, false);
   }
 }
Beispiel #2
0
  private void writeImage(
      final File file,
      byte[] data,
      final int xsize,
      final int ysize,
      final int zsize,
      final boolean yflip)
      throws IOException {
    // Input data is in RGBRGBRGB or RGBARGBARGBA format; first unswizzle it
    final byte[] tmpData = new byte[xsize * ysize * zsize];
    int dest = 0;
    for (int i = 0; i < zsize; i++) {
      for (int j = i; j < (xsize * ysize * zsize); j += zsize) {
        tmpData[dest++] = data[j];
      }
    }
    data = tmpData;

    // requires: DATA must be an array of size XSIZE * YSIZE * ZSIZE,
    //           indexed in the following manner:
    //             data[0]    ...data[xsize-1] == first row of first channel
    //             data[xsize]...data[2*xsize-1]   == second row of first channel
    //         ... data[(ysize - 1) * xsize]...data[(ysize * xsize) - 1] ==
    //                                            last row of first channel
    //           Later channels follow the same format.
    //           *** NOTE that "first row" is defined by the BOTTOM ROW of
    //           the image. That is, the origin is in the lower left corner.
    // effects: writes out an SGI image to FILE, RLE-compressed, INCLUDING
    //          header, of dimensions (xsize, ysize, zsize), and containing
    //          the data in DATA. If YFLIP is set, outputs the data in DATA
    //          in reverse order vertically (equivalent to a flip about the
    //          x axis).

    // Build the offset tables
    final int[] starttab = new int[ysize * zsize];
    final int[] lengthtab = new int[ysize * zsize];

    // Temporary buffer for holding RLE data.
    // Note that this makes the assumption that RLE-compressed data will
    // never exceed twice the size of the input data.
    // There are surely formal proofs about how big the RLE buffer should
    // be, as well as what the optimal look-ahead size is (i.e. don't switch
    // copy/repeat modes for less than N repeats). However, I'm going from
    // empirical evidence here; the break-even point seems to be a look-
    // ahead of 3. (That is, if the three values following this one are all
    // the same as the current value, switch to repeat mode.)
    final int lookahead = 3;
    final byte[] rlebuf = new byte[2 * xsize * ysize * zsize];

    int cur_loc = 0; // current offset location.
    int ptr = 0;
    int total_size = 0;
    int ystart = 0;
    int yincr = 1;
    int yend = ysize;

    if (yflip) {
      ystart = ysize - 1;
      yend = -1;
      yincr = -1;
    }

    final boolean DEBUG = false;

    for (int z = 0; z < zsize; z++) {
      for (int y = ystart; y != yend; y += yincr) {
        // RLE-compress each row.

        int x = 0;
        byte count = 0;
        boolean repeat_mode = false;
        boolean should_switch = false;
        final int start_ptr = ptr;
        int num_ptr = ptr++;
        byte repeat_val = 0;

        while (x < xsize) {
          // see if we should switch modes
          should_switch = false;
          if (repeat_mode) {
            if (imgref(data, x, y, z, xsize, ysize, zsize) != repeat_val) {
              should_switch = true;
            }
          } else {
            // look ahead to see if we should switch to repeat mode.
            // stay within the scanline for the lookahead
            if ((x + lookahead) < xsize) {
              should_switch = true;
              for (int i = 1; i <= lookahead; i++) {
                if (DEBUG)
                  System.err.println(
                      "left side was "
                          + ((int) imgref(data, x, y, z, xsize, ysize, zsize))
                          + ", right side was "
                          + (int) imgref(data, x + i, y, z, xsize, ysize, zsize));

                if (imgref(data, x, y, z, xsize, ysize, zsize)
                    != imgref(data, x + i, y, z, xsize, ysize, zsize)) should_switch = false;
              }
            }
          }

          if (should_switch || (count == 127)) {
            // update the number of elements we repeated/copied
            if (x > 0) {
              if (repeat_mode) rlebuf[num_ptr] = count;
              else rlebuf[num_ptr] = (byte) (count | 0x80);
            }
            // perform mode switch if necessary; output repeat_val if
            // switching FROM repeat mode, and set it if switching
            // TO repeat mode.
            if (repeat_mode) {
              if (should_switch) repeat_mode = false;
              rlebuf[ptr++] = repeat_val;
            } else {
              if (should_switch) repeat_mode = true;
              repeat_val = imgref(data, x, y, z, xsize, ysize, zsize);
            }

            if (x > 0) {
              // reset the number pointer
              num_ptr = ptr++;
              // reset number of bytes copied
              count = 0;
            }
          }

          // if not in repeat mode, copy element to ptr
          if (!repeat_mode) {
            rlebuf[ptr++] = imgref(data, x, y, z, xsize, ysize, zsize);
          }
          count++;

          if (x == xsize - 1) {
            // Need to store the number of pixels we copied/repeated.
            if (repeat_mode) {
              rlebuf[num_ptr] = count;
              // If we ended the row in repeat mode, store the
              // repeated value
              rlebuf[ptr++] = repeat_val;
            } else rlebuf[num_ptr] = (byte) (count | 0x80);

            // output zero counter for the last value in the row
            rlebuf[ptr++] = 0;
          }

          x++;
        }
        // output this row's length into the length table
        final int rowlen = ptr - start_ptr;
        if (yflip) lengthtab[ysize * z + (ysize - y - 1)] = rowlen;
        else lengthtab[ysize * z + y] = rowlen;
        // add to the start table, and update the current offset
        if (yflip) starttab[ysize * z + (ysize - y - 1)] = cur_loc;
        else starttab[ysize * z + y] = cur_loc;
        cur_loc += rowlen;
      }
    }

    // Now we have the offset tables computed, as well as the RLE data.
    // Output this information to the file.
    total_size = ptr;

    if (DEBUG) System.err.println("total_size was " + total_size);

    final DataOutputStream stream =
        new DataOutputStream(new BufferedOutputStream(IOUtil.getFileOutputStream(file, true)));

    writeHeader(stream, xsize, ysize, zsize, true);

    final int SIZEOF_INT = 4;
    for (int i = 0; i < (ysize * zsize); i++)
      stream.writeInt(starttab[i] + 512 + (2 * ysize * zsize * SIZEOF_INT));
    for (int i = 0; i < (ysize * zsize); i++) stream.writeInt(lengthtab[i]);
    for (int i = 0; i < total_size; i++) stream.write(rlebuf[i]);

    stream.close();
  }